A Hartig net is a complex of fungal hyphae found in the intercellular spaces between the cortical cells of a root. In some cases the Hartig net may cover the plant cell to the extent that the cell has no contact with other root cells. The massive surface area provided by the Hartig net is the main place for exchange of substances between the plant and fungus. The fungal sheath around a root suppresses the development of root hairs in the plant which makes the plant increasingly dependant upon the fungus for most of its nutritional needs. The fungal sheath also reduces that rate of plant cell division at the root tip causing them to become short and appear stunted. In addition, the sheath stores energy from the carbohydrates initially received from the plant, acting as an energy (carbon) sink.